PROPAGATION. 



225 



cially to annuals and biennials. With regard to 

 trees and shrubs, it is, generally speaking, well 

 to adopt the natural period of sowing if circum- 

 stances will permit. At the same time it is 

 desirable that the seedlings should make their 

 appearance at the season which is favourable to 

 their growth. Accordingly those seeds which 

 do not keep well dry are committed to the 

 soil, or mixed with it, in autumn, but their 

 vegetation is not encouraged till spring. 



In nurseries where large quantities of these 

 seeds are annually sown they are treated as 

 follows : A heap of fine soil is prepared, and the 

 seeds are thoroughly mixed with it. The whole 

 is then heaped up in the form of a cone and 

 allowed to remain thus for a year, when the 

 cone is broken up, and the seeds sown in the 

 ordinary way. This treatment hastens ger- 

 mination, and preserves the seeds from vermin 

 and bad weather, to which it would fall a prey 

 if sown in the usual way. 



The ' rot heap ' is another method of hasten- 

 ing the germination of seeds, which, sown in 

 the ground in the ordinary manner, would lie for 

 years perhaps before germinating. The seeds 

 are thoroughly soaked in hot water, and then 

 mixed with sand or light soil. The whole is then 

 buried in the ground, where the seeds will keep 

 moist, and they remain there twelve months, 

 when they are taken up and sown in beds in 

 the ordinary way. Thus treated, the seeds ger- 

 minate in a few weeks after they are finally 

 sown. The seeds for which this process is 

 employed are those of Crataegus, Juniperus, 

 Taxus, Cotoneaster, Plum, Pear, Rose, and 

 Holly, the seeds of which have a hard, bony 

 testa. 



Temperature has much to do with the length 

 of time that seeds require to vegetate and appear 

 above-ground. The seeds of Apples and Pears, 

 if sown without any previous preparation, do 

 not rise till the second year; but if previously 

 washed, in order to remove a sort of mucilage 

 which surrounds them and seems to be impene- 

 trable to the action of the air and moisture, 

 they then rise very well in the first year. In 

 the same way many seeds that do not rise till 

 the second year, if steeped for twenty -four 

 hours, then rubbed slightly, and sown in heat, 

 will rise the same year. The seeds of Pears thus 

 treated have been raised in seventeen days, and 

 the seed of Grapes in a month. Seeds of choice 

 or new plants of which a stock is required as 

 speedily as possible should be sown in warmth, 

 and in this way much time is gained. Thus, 

 Rhododendrons, Roses, Conifers, Leguminous 

 Vol. I. 



trees and shrubs, are rapidly propagated by this 

 means. Care is necessary in hardening them 

 off so that the forcing treatment shall not have 

 a weakening effect upon the seedlings. 



Herr Max Leichtlin, one of the most success- 

 ful growers and propagators of hardy plants, 

 writing in 1891 said: "If practicable, it would 

 be best to sow all seeds of hardy plants at once 

 when ripe ; we only delay sowing for the sake of 

 convenience, because we should, in the case of 

 autumnal sowings, be obliged to house a very 

 large number of pans and boxes of young plants 

 too small to pass the winter outside. Hard- 

 shelled seeds must be sown at once, also all 

 seeds of hardy bulbous plants. If seeds of Col- 

 chicum be exposed to the air for a few days, not 

 more than five per cent come up within a year, 

 and the rest may take five years to germinate, 

 whereas, sown as soon as the seed-pod splits, 

 thirty per cent will germinate in the first year. 

 Delay sowing the seeds of Lilium, Fritillaria, 

 Tulipa, &c, and you will lose from twenty to 

 eighty per cent. Campanulas and Ostrowskya 

 readily germinate when sown at once, but if 

 sowing is deferred till spring the seeds will 

 probably lie dormant for a year, if they do not 

 perish altogether." 



Frost sometimes has a powerful influence on 

 the germination of seeds which are otherwise 

 slow to move. The seeds of Kniphofia, TropcBO- 

 lum azureum, T. tricolor, and Tecojihilcea cyano- 

 crocus germinate much quicker after the soil in 

 which they were sown has been frozen. 



On the other hand, excessive heat is often an 

 advantage. All the seeds of Leguminosse, which 

 have hard testa (shells), before being sown 

 should be soaked for a few hours in water that 

 is nearly boiling. In a state of nature the testa 

 never becomes so hard and bony as it does when 

 exposed to drought for a time. Thus the seeds 

 of Nelumbium, which naturally drop into the 

 mud below as soon as they are ripe, where they 

 soon germinate, become very hard with expo- 

 sure, and the embryo is unable to push its way 

 through the bone-like testa, so that it is neces- 

 sary before sowing the seeds to rub them on a 

 file or grindstone until the embryo is exposed. 



4. Modes of Sotting in the Open Air. — There 

 are two principal ways of sowing — broadcast, or 

 in drills or rows. Broadcast sowing is merely 

 scattering the seeds over the surface, and is 

 doubtless the most original. But the drill 

 system is now generally adopted, both in the 

 garden and in the field. It has the advantage 

 of admitting of the ground being more expe- 

 ditiously cleaned and stirred in the intervals, 



15 



